Prior to the 1960's, slightly abrasive, dental prophylaxis paste used by dental practitioners, i.e., dentists or dental hygienists, to clean teeth of patients was prepared in situ at the time needed, by mixing a dry abrasive material with a wetting agent. This was typically done by a dental assistant. Because this required preparation time, a practicing dentist in the 1960's developed a product which was previously mixed into a paste and placed in small, cylindrical, cup-shaped containers having peripheral flanges, each cup being approximately one-half inch in diameter and having a sterile removable cover sheet thereover. These were prepared and sold to dentists in substantial numbers. A large number of these containers were actually formed simultaneously in each sheet of polymeric sheet stock, the containers then being filled en masse and covered with a removable sterile adhesive sheet. The multiple of containers in the sheet were separated along die cut patterns so that each prophylaxis paste cup-type container could be utilized individually.
To hold the small prophylaxis paste containers when cleaning teeth using a conventional powered buffing tool, a finger ring retainer of the type shown in FIG. 11 was developed and provided. These finger ring retainers were made by forming a sheet of metal into L-shaped segments with a punch press (FIGS. 12 and 13), i.e., each segment having a pair of legs, deburring the segments to rid them of the die cut sharp edges, cleaning the punch press oil from the segments, polishing the segments, and then bending the legs of the individual segments into arcuate, almost circular, configurated ends, so that one end would hold the prophylaxis cup and the other end could be placed around a finger of the dental practitioner.
These ring forming procedures resulted in considerable processing costs for the multiple steps required, and resulted in substantial scrap metal around the L-shaped stampings. Molded polymeric alternatives to this earlier metal ring were also provided to the market in recent years.